This invention relates to a variable venturi carburetor for an internal combustion engine, and more particularly to the variable venturi carburetor which prevents the influence of fuel bubbles created during engine running operation, especially under a heavy load condition so as to attain the stablization and improvement of engine power.
In a traditional variable venturi carburetor, especially during engine running operation under a heavy load condition, the atomized fuel stored in a fuel well of a fuel jet installed in the carburetor is vaporized to create fuel bubbles under the influence of vibration or pulsation of the engine, or increase in engine temperature. Such fuel bubbles are filled in the fuel well and intermittently delivered from a fuel metering portion of the fuel jet. As the result, an air-fuel ratio disadvantageously varies and the preset air-fuel ratio cannot be maintained constant for each engine running operation, or the drivability is likely to deteriorate during an engine running operation under a heavy load condition (see FIG. 7).